Radio frequency (RF) identification systems use contactless information acquisition technologies to identify objects at a distance and out of a line of sight. Such systems generally comprise RF transponders (“radio frequency identification” (RFID) devices, RF interrogators (“readers”) of the RFID devices, and a controller with a computerized database. The RFID devices typically are incorporated in credit card-like plastic enclosures (e.g., smart cards, ID/access cards, and the like) or directly attached, in a form of RF tags, to the products being monitored or packages thereof. In operation, the RFID device is presented to a reader that reads data from the RFID device, transmits the data to a controller or host system, where a decision is made to grant or deny access to an asset, such as a secure location or some sort of device like a computer. The controller may be centralized and communicate with a plurality of readers or it may be localized and associated with a single reader. The latter is referred to as a stand-alone reader.
In the present state-of-the-art, cards contain data that is promiscuously transmitted when it is excited by being in close proximity to the reader. The data is transmitted from the first memory location in the card and continues with the next sequential memory location until a preprogrammed upper limit is reached. This process repeats continuously restarting at the first memory location after the upper limit has been reached until the card is removed from the reader's RF field. The reader receives and stores multiple continuous transmissions and looks for a synchronization sentinel indicating where the data begins. It then makes sure that a minimum number of identical instances of the data are present to insure that there have been no data reception errors. The data is then formatted and transmitted via a communications port to an upstream device for processing and interpretation of the data. As previously noted, the upstream device may be a remote controller, such as a control panel or host computer, or it may be localized with the reader.
A format is a container for the data that defines its content and size. The supplier and user of the access control system chooses which format is the most suitable based upon the desired data content as well as considerations for security of the data. Due to historical and legacy considerations, the number of bits utilized in formats typically range from 26 to 40 bits, although persons of skill in the art will recognize that the number of bits may exceed 40. Formats that are popular, such as the “26-bit Wiegand format” are less secure than formats that contain a larger number of data bits due to the fact that with a relatively few number of bits, the possibility of finding identical cards in a large world-wide card population for a given format is statistically very likely.
In one specific application, the RFID devices are used in automated security systems providing controlled access to (or exit from) areas, such as offices, public or commercial buildings, and the like. In this and similar applications, integrity of an automated security system may be compromised by attackers eavesdropping RF communications between the RFID device and the reader and cloning a legitimate RFID device, as well as electronically or otherwise tampering with the reader or replacing the reader with a fraudulent device.
RFID cards have become a very mature, reliable, convenient, and popular technology and, as a result, a large installed base of older cards and readers exists (legacy cards and readers). Adding or updating security in older systems such as these can be difficult, expensive, and time consuming. What used to be state of the art security technology twenty or even ten years ago is becoming outdated and less secure.
Conventional systems have several weaknesses that can be exploited since no authentication of the card is performed. Such weaknesses include, substitution of a legitimate reader with an unauthorized reader, substitution of a bona-fide card with a clone, reading a card programmed by an illicit source, and reading a card programmed by an unscrupulous or even low cost supplier that does not have the same quality and security measures therein. Additionally, RFID cards that promiscuously emit unchanging or static data are subject to replay attacks in which a device pretends to be a legitimate reader in order to acquire the promiscuous data. An attacker only needs to read the RFID cards of a passerby or simply borrow a legitimate user's card to harvest data from it for later re-use.
While there is a constant trend of increased sophistication in attempts to compromise the security systems, the high cost of replacing a network of existing readers with more advanced RF interrogators may delay the response to detected and anticipated security threats or violations. Such existing readers or systems may be referred to as legacy readers or systems. They typically are not state of the art in their functionality and features.
Ultimately, legacy readers, systems, cards, and protocols need to be replaced or updated with newer more secure identification and/or security systems. As noted above, this transition can be a very expensive process, especially when a large installed base of legacy readers and cards exists. For example, in the event that a large entity wishes to update their security system, immediate replacement of thousands of readers and security credentials would be impossible. Even if the transition were performed over the course of a week, that week would provide a window where potential attackers could gain unauthorized access to previously secured assets. There are also other entities that do not wish to completely update their entire security systems at once. These entities require a technology that can work according to both the old legacy system protocols and the new system protocols.
There is also a threat that older attacking methods may be used to gain illicit access to assets in an updated system. Both fully updated systems and partially updated systems are still susceptible to the old methods employed by attackers to gain access or information from security systems. For example, attackers may attempt to use older legacy readers in order to recover promiscuously transmitted information from genuine access cards. The promiscuous data may be stolen from a legacy card and placed on an illicit card or portable electronic emulation device. An attacker then only has to present the illicit card to a remote reader that has not been updated and the reader cannot tell the difference between the illicit card and the genuine card because each contains the same data. Also, attackers may attempt to replace or bypass the new reader with a legacy reader by tapping into the communication lines between the reader and the controller.
Therefore, there is a need in the art for an improved system and method for authenticating the RFID devices and validating the readers of the RFID devices, especially during, or after completion of, an upgrade of technology in identification systems.